This invention relates to radar systems and particularly, though not exclusively, to CW radar systems.
Clutter is a problem which affects all radar systems having co-located transmit and receive antennae, and is caused by the reflection of transmitted radiation from stationary objects close to the antennae. Clutter masking systems have been developed, particularly for pulse radars, and usually rely on recording the location of an object causing clutter in terms of antenna bearing (azimuth) and range. In a CW radar, instantaneous values of range are not readily available, and such techniques as do exist for determining range are generally too slow in response for the generation of clutter masks in the presence of moving targets. These techniques also produce what is known as the "doppler blind zone" within which genuine moving targets cannot be detected.
It is an object of the invention to provide a radar system having clutter-suppression arrangements which may be applied to CW radar as well as pulse radar.